"If it's going to be -4 wind chill and they're standing out there and the bus is late 5, 10, 15 minutes, then that's a little too cold for them to be out there. They don't have the gloves and the hats, ski jackets that you'll typically find up north," said Mark Lindstrom with the Transportation Department at Marietta School District.

Henry County echoed the sentiment in a written statement.
"The decision to close schools is one that is not taken lightly. Many people are impacted by the decision that is made, no matter what that is. With nearly 60% of our student population reliant upon bus transportation, having them exposed to such extreme temperatures while waiting on the bus was something that could prove hazardous," said spokesman John Hardin.

Plus districts say, there's no guarantees all of the buses tested on Monday will work in the cold weather Tuesday.

The diesel fuel used in many school buses throughout metro Atlanta can begin to gel at 20 degrees, unless an additives is put in with the fuel.

The additive can cost around $70 per bus and has to be added every time they fill up. Many districts say they plan to do so before Wednesday's bus routes as a safety measure against break downs, even though temperatures will be a bit warmer.

In Gwinnett county, more than 70% students ride the bus. And while the district is eager to get back to class, schools will have to sit quiet one more day.

"Safety, that's the main reason. Safety," said district spokesman Jorge Quintana.